This invention relates to an improved multi-stage click switch which produces a suitable click feeling in a multi-stage manner when operating an operation knob.
As shown in FIGS. 9 and 10, one example of related switches for controlling the operation of various electric equipments (such as a power window mechanism), mounted, for example, on a door trim of a car door, is a two-stage click switch 1 which produces a suitable click feeling when pivotally operating an operating knob 11.
This two-stage click switch 1 disclosed in Japanese Patent No. 2792571, comprises: a housing 2; a pair of pressing members 10 and 12 forwardly and backwardly-movably mounted on the housing 2 in spaced relation to each other; the operating knob 11 for moving the pressing members 10 and 12 downward; a contact circuit member 3, which is mounted on the housing 2 in opposed relation to the pressing members 10 and 12 and the operating knob 11, and has two pairs of contact portions 14a, 14b and 16a, 16b each pair of which are disposed in opposed relation to a respective one of the pressing members 10 and 12; and a rubber switch member 9 provided between the contact circuit member 3 and the pressing members 8 and 10.
The rubber switch member 9 has two pairs of rubber contact portions 5a, 5b and 7a, 7b each pair of which can sequentially close and open the corresponding pair of contact portions 14a and 14b (16a and 16b) upon forward and backward movement of the corresponding pressing member 8, 10. A pair of conductive pieces 6a and 6b (8a and 8b) are provided within each pair of rubber contact portions 5a and 5b (7a and 7b), respectively, in opposed relation to the contact portions 14a and 14b (16a and 16b). The distance L1 between the conductive piece 6a, 8a and the contact portion 14a, 16a is smaller than the distance L2 between the other conductive piece 6b, 8b and the contact portion 14b, 16b (L1<L2)
The rubber contact portion 5a, 7a, after pressed into contact with the contact portion 14a, 16a, can still advance a small distance, and the rubber contact portion 5a, 7a of the overstroke type can absorb an operating stroke difference due to the distances L1 and L2. Namely, the rubber contact portion 5a, 7a includes two-stage operating means 19 which is operable in a two-stage manner while absorbing the operating stroke difference.
The operating knob 11 is pivotally supported by a pair of support shafts 2a and 2a formed on the housing 2. The operating knob, when pivotally moved in a clockwise direction (FIG. 9), advances the pressing member 12, thereby moving a window glass pane upward, and when this operating knob is pivotally moved in a counterclockwise direction, it advances the pressing member 10, thereby moving the window glass pane downward.
For example, when the operating knob 11 is pivotally moved in the clockwise direction (FIG. 9), the pressing member 12 advances downward to descend the rubber contact portions 7a and 7b. In this descending operation, the conductive piece 8a is first pressed into contact with the manually-ascending contact portion 16a to achieve a first-stage operating condition, thereby rendering this contact portion into a conducting state. When this condition is maintained, the window glass pane is ascending.
Then, when the operating knob 11 is returned to its initial position, the conductive piece 8a moves upward apart from the contact portion, so that the window glass pane ceases to ascend. Alternatively, when the operating knob 11 is further pivotally moved through a predetermined angle in the clockwise direction, the rubber contact portion 7a, serving as the two-stage operating means 19, is further flexed after the above press contact, thereby absorbing the stroke difference, so that the rubber contact portion 7b continues to descend, and the conductive piece 8b is pressed into contact with the automatically-ascending contact portion 16b to achieve a second-stage operating condition, and the window glass pane automatically moves upward to an upper limit.
In the case of the switch thus operable in a two-stage manner, unless a click feeling, capable of detecting the operating condition of each stage, is provided, an operation error is incurred.
Therefore, the operating knob 11 is provided with a click producing mechanism 18 which comprises a compression spring 15 and a pin 13 which are provided in a mounting hole provided at a central portion of the operating knob. A suitable click feeling can be obtained by the friction between the pressing pin 13 and a V-shaped receiving groove 17. Each of the rubber contact portions 5a, 5b, 7a and 7b has a generally bowl-shaped cross-section, and is of the clickless type so as to be elastically deformed without affecting a click feeling produced by the click producing mechanism 18.
However, since the pressing pin 13 and the compression spring 15 of the click producing mechanism 18 are contained in the operating knob 11, the height dimension of the operating knob 11 increases.
Therefore, the pressing member 10, 12 for transmitting the pressing force need to be provided between the rubber contact portions 5a and 5b (7a, 7b) and a rubber switch pressing portion 11a, 11b. 
Therefore, the number of the component parts of the two-stage click switch 1 increases because of the component parts of the click producing mechanism 18 and the pressing members 10 and 12, so that it is encountered a problem that the time and labor, required for the assembling operation, increased, and the production cost increases.
Further, the two-stage click switch 1 makes it difficult to form the whole of the unit into a compact design (for example, a space-saving design when it is mounted on a vehicle).